vSphere High Performance Cookbook - Second Edition
¥90.46
Over 80 recipes to help you improve vSphere 6.5's performance and solve problems before they arise About This Book ? The practical recipes provide cost-effective and high performance for any application running in a virtual machine ? Contains best practices and troubleshooting techniques to resolve vSphere 6.5 performance issues ? Get a comprehensive coverage of performance issues and solutions including vCenter Server design and virtual machine and application tuning Who This Book Is For If you are a system administrator and are planning to deploy vSphere 6.5 in your organization and want to maximize its performance, then this book is for you. Prior knowledge of the vSphere 6.5 concepts is essential. What You Will Learn ? Understand the VMM Scheduler, cache aware CPU Scheduler, NUMA aware CPU Scheduler, and more during the CPU Performance Design phase ? Get to know the virtual memory reclamation technique, host ballooning monitoring, and swapping activity ? Choose the right platform while designing your vCenter Server, redundant vCenter design, and vCenter SSO and its deployment ? Learn how to use various performance simulation tools ? Design VCSA Server Certificates to minimize security threats ? Use health check tools for storage and boost vSphere 6.5's performance with VAAI and VASA In Detail vSphere is a mission-critical piece of software for many businesses. It is a complex tool, and incorrect design and deployment can create performance related issues that can negatively affect the business. This book is focused on solving these problems as well as providing best practices and performance-enhancing techniques. This edition is fully updated to include all the new features in version 6.5 as well as the latest tools and techniques to keep vSphere performing at its best. This book starts with interesting recipes, such as the interaction of vSphere 6.5 components with physical layers such as CPU, memory, and networking. Then we focus on DRS, resource control design, and vSphere cluster design. Next, you'll learn about storage performance design and how it works with VMware vSphere 6.5. Moving on, you will learn about the two types of vCenter installation and the benefits of each. Lastly, the book covers performance tools that help you get the most out of your vSphere installation. By the end of this book, you will be able to identify, diagnose, and troubleshoot operational faults and critical performance issues in vSphere 6.5. Style and approach This cookbook is written in a practical, helpful style with numerous recipes focusing on answering and providing solutions to common and not-so-common performance issues and problems.
Practical Predictive Analytics
¥90.46
Make sense of your data and predict the unpredictable About This Book ? A unique book that centers around develop six key practical skills needed to develop and implement predictive analytics ? Apply the principles and techniques of predictive analytics to effectively interpret big data ? Solve real-world analytical problems with the help of practical case studies and real-world scenarios taken from the world of healthcare, marketing, and other business domains Who This Book Is For This book is for those with a mathematical/statistics background who wish to understand the concepts, techniques, and implementation of predictive analytics to resolve complex analytical issues. Basic familiarity with a programming language of R is expected. What You Will Learn ? Master the core predictive analytics algorithm which are used today in business ? Learn to implement the six steps for a successful analytics project ? Classify the right algorithm for your requirements ? Use and apply predictive analytics to research problems in healthcare ? Implement predictive analytics to retain and acquire your customers ? Use text mining to understand unstructured data ? Develop models on your own PC or in Spark/Hadoop environments ? Implement predictive analytics products for customers In Detail This is the go-to book for anyone interested in the steps needed to develop predictive analytics solutions with examples from the world of marketing, healthcare, and retail. We'll get started with a brief history of predictive analytics and learn about different roles and functions people play within a predictive analytics project. Then, we will learn about various ways of installing R along with their pros and cons, combined with a step-by-step installation of RStudio, and a de*ion of the best practices for organizing your projects. On completing the installation, we will begin to acquire the skills necessary to input, clean, and prepare your data for modeling. We will learn the six specific steps needed to implement and successfully deploy a predictive model starting from asking the right questions through model development and ending with deploying your predictive model into production. We will learn why collaboration is important and how agile iterative modeling cycles can increase your chances of developing and deploying the best successful model. We will continue your journey in the cloud by extending your skill set by learning about Databricks and SparkR, which allow you to develop predictive models on vast gigabytes of data. Style and Approach This book takes a practical hands-on approach wherein the algorithms will be explained with the help of real-world use cases. It is written in a well-researched academic style which is a great mix of theoretical and practical information. Code examples are supplied for both theoretical concepts as well as for the case studies. Key references and summaries will be provided at the end of each chapter so that you can explore those topics on their own.
Python Machine Learning By Example
¥90.46
Take tiny steps to enter the big world of data science through this interesting guide About This Book ? Learn the fundamentals of machine learning and build your own intelligent applications ? Master the art of building your own machine learning systems with this example-based practical guide ? Work with important classification and regression algorithms and other machine learning techniques Who This Book Is For This book is for anyone interested in entering the data science stream with machine learning. Basic familiarity with Python is assumed. What You Will Learn ? Exploit the power of Python to handle data extraction, manipulation, and exploration techniques ? Use Python to visualize data spread across multiple dimensions and extract useful features ? Dive deep into the world of analytics to predict situations correctly ? Implement machine learning classification and regression algorithms from scratch in Python ? Be amazed to see the algorithms in action ? Evaluate the performance of a machine learning model and optimize it ? Solve interesting real-world problems using machine learning and Python as the journey unfolds In Detail Data science and machine learning are some of the top buzzwords in the technical world today. A resurging interest in machine learning is due to the same factors that have made data mining and Bayesian analysis more popular than ever. This book is your entry point to machine learning. This book starts with an introduction to machine learning and the Python language and shows you how to complete the setup. Moving ahead, you will learn all the important concepts such as, exploratory data analysis, data preprocessing, feature extraction, data visualization and clustering, classification, regression and model performance evaluation. With the help of various projects included, you will find it intriguing to acquire the mechanics of several important machine learning algorithms – they are no more obscure as they thought. Also, you will be guided step by step to build your own models from scratch. Toward the end, you will gather a broad picture of the machine learning ecosystem and best practices of applying machine learning techniques. Through this book, you will learn to tackle data-driven problems and implement your solutions with the powerful yet simple language, Python. Interesting and easy-to-follow examples, to name some, news topic classification, spam email detection, online ad click-through prediction, stock prices forecast, will keep you glued till you reach your goal. Style and approach This book is an enticing journey that starts from the very basics and gradually picks up pace as the story unfolds. Each concept is first succinctly defined in the larger context of things, followed by a detailed explanation of their application. Every concept is explained with the help of a project that solves a real-world problem, and involves hands-on work—giving you a deep insight into the world of machine learning. With simple yet rich language—Python—you will understand and be able to implement the examples with ease.
Progressive Web Apps with React
¥80.65
Enhance the performance of your applications by using React and adding the Progressive web app capability to it About This Book ? Bring the best of mobile sites and native apps to your users with progressive web applications ? Create fast, reliable, and engaging PWAs with React and Firebase ? Create high-performance applications even with low connection speeds by leveraging modern web technologies Who This Book Is For This book is for Java* Developers who want to develop high performance Web User Interfaces. This book requires basic knowledge of HTML, CSS and JavaScript. What You Will Learn ? Set up Webpack configuration, as well as get the development server running ? Learn basic Firebase configuration and deployment ? Create routes, manage multiple components, and learn how to use React Router v4 to manage the flow of data ? Use React life cycle methods to load data ? Add a service worker to the app and learn how it works ? Use a service worker to send Push Notifications ? Configure Webpack to split up the JavaScript bundle and lazy load component files ? Learn how to use the web Cache API to use your app offline ? Audit PWAs with Google's Lighthouse tool In Detail For years, the speed and power of web apps has lagged behind native applications. Progressive Web Apps (PWAs) aim to solve this by bridging the gap between the web apps and native apps, delivering a host of exciting features. Simultaneously, React is fast becoming the go-to solution for building modern web UIs, combining ease of development with performance and capability. Using React alongside PWA technology will make it easy for you to build a fast, beautiful, and functional web app. After an introduction and brief overview of the goals of PWAs, the book moves on to setting up the application structure. From there, it covers the Webpack build process and the process of creating React components. You'll learn how to set up the backend database and authentication solution to communicate with Firebase and how to work with React Router. Next, you will create and configure your web app manifest, making your PWA installable on mobile devices. Then you'll get introduced to service workers and see how they work as we configure the app to send push notifications using Firebase Cloud Messaging. We'll also explore the App Shell pattern, a key concept in PWAs and look at its advantages regarding efficient performance. Finally, you'll learn how to add offline capabilities to the app with caching and confirm your progress by auditing your PWA with Lighthouse. Also, you'll discover helper libraries and shortcuts that will help you save time and understand the future of PWA development. Style and approach This is a step-by-step book, wherein, you will use the React framework to create a complete progressive web app.
Building Web and Mobile ArcGIS Server Applications with JavaScript - Second Edit
¥90.46
Master the ArcGIS API for JavaScript to build web and mobile applications using this practical guide. About This Book ? Develop ArcGIS Server applications with JavaScript, both for traditional web browsers as well as the mobile platform ? Make your maps informative with intuitive geographic layers, user interface widgets, and more ? Integrate ArcGIS content into your custom applications and perform analytics with the ArcGIS Online Who This Book Is For If you are a web or mobile application developer, who wants to create GIS applications in your respective platform, this book is ideal for you. You will need Java Script programming experience to get the most out of this book. Although designed as an introductory to intermediate level book, it will also be useful for more advanced developers who are new to the topic of developing applications with ArcGIS Server. What You Will Learn ? To create an application with the ArcGIS API for JavaScript ? Build and display a broad range of different geometry types to represent features on the map ? The best way to leverage a feature layer and display related attribute data ? The functionality of the wide range of widgets and how to use them effectively ? Query data to gain new insights into the information it contains ? Work with tasks to discover and locate features on the map ? Using the geocoder and associated widgets ? The ability of the API to provide turn by turn directions and routing capabilities ? How to use the Geometry Engine and Geometry Service tasks for common geoprocessing operations ? Integrate content on ArcGIS online and add it to your custom web mapping application In Detail The ArcGIS API for JavaScript enables you to quickly build web and mobile mapping applications that include sophisticated GIS capabilities, yet are easy and intuitive for the user. Aimed at both new and experienced web developers, this practical guide gives you everything you need to get started with the API. After a brief introduction to HTML/CSS/JavaScript, you'll embed maps in a web page, add the tiled, dynamic, and streaming data layers that your users will interact with, and mark up the map with graphics. You will learn how to quickly incorporate a broad range of useful user interface elements and GIS functionality to your application with minimal effort using prebuilt widgets. As the book progresses, you will discover and use the task framework to query layers with spatial and attribute criteria, search for and identify features on the map, geocode addresses, perform network analysis and routing, and add custom geoprocessing operations. Along the way, we cover exciting new features such as the client-side geometry engine, learn how to integrate content from ArcGIS.com, and use your new skills to build mobile web mapping applications. We conclude with a look at version 4 of the ArcGIS API for JavaScript (which is being developed in parallel with version 3.x) and what it means for you as a developer. Style and approach Readers will be taken through a series of exercises that will demonstrate how to efficiently build ArcGIS Server applications for the mobile and web.
Test-Driven iOS Development with Swift 4 - Third Edition
¥71.93
Use test-driven approach to develop highly-functional iOS apps with Swift 4 and Xcode 9 About This Book ? A practical guide to writing effective, organized, and clean code that works well ? Learn test-driven principles to help you build better-designed apps with fewer bugs ? A comprehensive overview of the techniques available for TDD in Swift Who This Book Is For To get the most out of this book, you will need some prior experience with Swift application development. You may have already heard about Test-Driven Development (TDD) but you don't need any prior experience of applying it to Swift applications. What You Will Learn ? Implement TDD in Swift application development ? Find bugs before you enter code using the TDD approach ? Use TDD to build models, view controllers, and views ? Test network code with asynchronous tests and stubs ? Write code that is a joy to read and maintain ? Develop functional tests to ensure the app works as planned In Detail Test-driven development (TDD) is a proven way to find software bugs early. Writing tests before you code improves the structure and maintainability of your apps. Using TDD, in combination with Swift 4's improved syntax, means there is no longer any excuse for writing bad code. This book will help you understand the process of TDD and how to apply it to your apps written in Swift. Through practical, real-world examples, you’ll learn how to implement TDD in context. You will begin with an overview of the TDD workflow and then delve into unit-testing concepts and code cycles. You will also plan and structure your test-driven iOS app, and write tests to drive the development of view controllers and helper classes. Next, you’ll learn how to write tests for network code and explore how the test-driven approach—in combination with stubs—helps you write network code even before the backend component is finished. Finally, the book will guide you through the next steps to becoming a testing expert by discussing integration tests, Behavior Driven Development (BDD), open source testing frameworks, and UI Tests (introduced in Xcode 9). Style and approach Using a step-by-step approach, you will develop an entire iOS app using TDD. During the course of the book, you will explore different strategies for writing tests for models, View Controllers, and networking code.
Jenkins 2.x Continuous Integration Cookbook - Third Edition
¥90.46
Get a problem-solution approach enriched with code examples for practical and easy comprehension About This Book ? Explore the use of more than 40 best-of-breed plug-ins for improving efficiency ? Secure and maintain Jenkins 2.x by integrating it with LDAP and CAS, which is a Single Sign-on solution ? Efficiently build advanced pipelines with pipeline as code, thus increasing your team's productivity Who This Book Is For If you are a Java developer, a software architect, a technical project manager, a build manager, or a development or QA engineer, then this book is ideal for you. A basic understanding of the software development life cycle and Java development is needed, as well as a rudimentary understanding of Jenkins. What You Will Learn ? Install and Configure Jenkins 2.x on AWS and Azure ? Explore effective ways to manage and monitor Jenkins 2.x ? Secure Jenkins 2.x using Matrix-based Security ? Deploying a WAR file from Jenkins 2.x to Azure App Services and AWS Beanstalk ? Automate deployment of application on AWS and Azure PaaS ? Continuous Testing – Unit Test Execution, Functional Testing and Load Testing In Detail Jenkins 2.x is one of the most popular Continuous Integration servers in the market today. It was designed to maintain, secure, communicate, test, build, and improve the software development process. This book will begin by guiding you through steps for installing and configuring Jenkins 2.x on AWS and Azure. This is followed by steps that enable you to manage and monitor Jenkins 2.x. You will also explore the ways to enhance the overall security of Jenkins 2.x. You will then explore the steps involved in improving the code quality using SonarQube. Then, you will learn the ways to improve quality, followed by how to run performance and functional tests against a web application and web services. Finally, you will see what the available plugins are, concluding with best practices to improve quality. Style and approach This book provides a problem-solution approach to some common tasks and some uncommon tasks using Jenkins 2.x and is well-illustrated with practical code examples.
Switching to Angular - Third Edition
¥54.49
Switching to Angular, Third Edition is the go-to book to align and get started with the Angular JavaScript framework. Angular contributor and international speaker Minko Gechev will help you square up and start building Angular apps and provide you an insight to the Google’s vision for the framework. About This Book ? Get up to date with Google’s vision for Angular ? Align with Angular version 5 and beyond from any direction with confidence ? Start using TypeScript to supercharge your Angular applications ? Understand the new framework from AngularJS perspective using your prior experience ? Use Angular to quickly build fast and scalable enterprise applications Who This Book Is For This book is for software developers who want to align with a modern version of Angular that’s aligned with Google’s vision of Angular version 5 and beyond, using stable APIs that they can depend on today and in the future. Also for anyone assessing changes to Angular and squaring up for a strategic migration to Angular v5, and for AngularJS developers who want to transfer their mindset to modern Angular version 5 and beyond. What You Will Learn ? Align with Google’s vision for Angular version 5 and beyond ? Confidently move forwards with a long-term understanding of Angular ? Use stable APIs in Angular to build future-proof, blazingly fast, enterprise applications ? Work with TypeScript to supercharge your Angular applications ? Understand the core concepts of Angular, aligned with the vision from Google ? Be ready with Angular from any direction - whether you’re building new new apps with the Angular and ASP.NET stack or upgrading from AngularJS with ngUpgrade In Detail Align your work to stable APIs of Angular, version 5 and beyond, with Angular expert Minko Gechev. Angular is the modern Google framework for you to build high-performing, SEO-friendly, and robust web applications. Switching to Angular, Third Edition shows you how you can align your current and future development with Google’s long term vision for Angular. Gechev shares his expert knowledge and community involvement to give you the clarity you need to confidently switch into Angular and stable APIs. Minko Gechev helps you square up to Angular with an overview of the framework, and understand the long term building blocks of Google’s web framework. Gechev then gives you the lowdown on TypeScript, with a crash-course so you can take advantage of Angular in its native, statically-typed environment. You’ll next move on to see how you can line up with Angular dependency injection, plus how Angular router and forms, and Angular pipes, are designed to work for your projects today and in the future. You'll be squared up and aligned with the vision and techniques of the one Angular, and be ready to start building quick and efficient Angular applications. You’ll know how to take advantage of the latest Angular features, and the core, stable APIs that you can depend on. You’ll be ready to confidently plan your future with the Angular framework. Style and approach In this book, Minko Gechev continues his direct style of sharing knowledge about Angular that he's developed across more than 40 international presentations to Angular developers. First, Minko explains Google's vision of Angular to you, and then you dive into a clear tutorial to work with Angular that's aligned with Google's vision of Angular.
Serverless computing in Azure with .NET
¥90.46
Harness the power of the Cloud, leveraging the speed and scale of Azure Serverless computing About This Book ? Take advantage of the agility, scale, and cost-effectiveness of the cloud using Azure Serverless compute ? Build scalable, reliable, and cost-effecient applications with Serverless architecture and .NET ? Learn to use Azure functions to their fullest potential in .NET Who This Book Is For This book is for .NET developers who would like to learn about serverless architecture. Basic C# programming knowledge is assumed. What You Will Learn ? Understand the best practices of Serverless architecture ? Learn how how to deploy a Text Sentiment Evaluation application in an Azure Serverless environment ? Implement security, identity, and access control ? Take advantage of the speed of deployment in the cloud ? Configure application health monitoring, logging, and alerts ? Design your application to ensure cost effectiveness, high availability, and scale In Detail Serverless architecture allows you to build and run applications and services without having to manage the infrastructure. Many companies have started adopting serverless architecture for their applications to save cost and improve scalability. This book will be your companion in designing Serverless architecture for your applications using the .NET runtime, with Microsoft Azure as the cloud service provider. You will begin by understanding the concepts of Serverless architecture, its advantages and disadvantages. You will then set up the Azure environment and build a basic application using a sample text sentiment evaluation function. From here, you will be shown how to run services in a Serverless environment. We will cover the integration with other Azure and 3rd party services such as Azure Service Bus, as well as configuring dependencies on NuGet libraries, among other topics. After this, you will learn about debugging and testing your Azure functions, and then automating deployment from source control. Securing your application and monitoring its health will follow from there, and then in the final part of the book, you will learn how to Design for High Availability, Disaster Recovery and Scale, as well as how to take advantage of the cloud pay-as-you-go model to design cost-effective services. We will finish off with explaining how azure functions scale up against AWS Lambda, Azure Web Jobs, and Azure Batch compare to other types of compute-on-demand services. Whether you’ve been working with Azure for a while, or you’re just getting started, by the end of the book you will have all the information you need to set up and deploy applications to the Azure Serverless Computing environment. Style and approach This step-by-step guide shows you the concepts and features of Serverless architecture in Azure with .NET.
Raspberry Pi Zero W Wireless Projects
¥63.21
Build DIY wireless projects using the Raspberry Pi Zero W board About This Book ? Explore the functionalities of the Raspberry Pi Zero W with exciting projects ? Master the wireless features (and extend the use cases) of this $10 chip ? A project-based guide that will teach you to build simple yet exciting projects using the Raspberry Pi Zero W board Who This Book Is For If you are a hobbyist or an enthusiast and want to get your hands on the latest Raspberry Pi Zero W to build exciting wireless projects, then this book is for you. Some prior programming knowledge, with some experience in electronics, would be useful. What You Will Learn ? Set up a router and connect Raspberry Pi Zero W to the internet ? Create a two-wheel mobile robot and control it from your Android device ? Build an automated home bot assistant device ? Host your personal website with the help of Raspberry Pi Zero W ? Connect Raspberry Pi Zero to speakers to play your favorite music ? Set up a web camera connected to the Raspberry Pi Zero W and add another security layer to your home automation In Detail The Raspberry Pi has always been the go–to, lightweight ARM-based computer. The recent launch of the Pi Zero W has not disappointed its audience with its $10 release. "W" here stands for Wireless, denoting that the Raspberry Pi is solely focused on the recent trends for wireless tools and the relevant use cases. This is where our book—Raspberry Pi Zero W Wireless Projects—comes into its own. Each chapter will help you design and build a few DIY projects using the Raspberry Pi Zero W board. First, you will learn how to create a wireless decentralized chat service (client-client) using the Raspberry Pi's features?. Then you will make a simple two-wheel mobile robot and control it via your Android device over your local Wi-Fi network. Further, you will use the board to design a home bot that can be connected to plenty of devices in your home. The next two projects build a simple web streaming security layer using a web camera and portable speakers that will adjust the playlist according to your mood. You will also build a home server to host files and websites using the board. Towards the end, you will create free Alexa voice recognition software and an FPV Pi Camera, which can be used to monitor a system, watch a movie, spy on something, remotely control a drone, and more. By the end of this book, you will have developed the skills required to build exciting and complex projects with Raspberry Pi Zero W. Style and approach A step-by-step guide that will help you design and create simple yet exciting projects using the Raspberry Pi Zero W board.
Exploring Experience Design
¥71.93
Learn how to unify Customer Experience, User Experience and more to shape lasting customer engagement in a world of rapid change. About This Book ? An introductory guide to Experience Design that will help you break into XD as a career by gaining A strong foundational knowledge ? Get acquainted with the various phases of a typical Experience Design workflow ? Work through the key process and techniques in XD, supported by most of the common use cases Who This Book Is For This book is for designers who wish to enter the field of UX Design, especially Programmers, Content Strategists, and Organizations keen to understand the core concepts of UX Design. What You Will Learn ? Understand why Experience Design (XD) is at the forefront of business priorities, as organizations race to innovate products and services in order to compete for customers in a global economy driven by technology and change ? Get motivated by the numerous professional opportunities that XD opens up for practitioners in wide-ranging domains, and by the stories of real XD practitioners ? Understand what experience is, how experiences are designed, and why they are effective ? Gain knowledge of user-centered design principles, methodologies, and best practices that will improve your product (digital or physical) ? Get to know your X’s and D’s—understand the differences between XD and UX, CX, IxD, IA, SD, VD, PD, and other design practices In Detail We live in an experience economy in which interaction with products is valued more than owning them. Products are expected to engage and delight in order to form the emotional bonds that forge long-term customer loyalty: Products need to anticipate our needs and perform tasks for us: refrigerators order food, homes monitor energy, and cars drive autonomously; they track our vitals, sleep, location, finances, interactions, and content use; recognize our biometric signatures, chat with us, understand and motivate us. Beautiful and easy to use, products have to be fully customizable to match our personal preferences. Accomplishing these feats is easier said than done, but a solution has emerged in the form of Experience design (XD), the unifying approach to fusing business, technology and design around a user-centered philosophy. This book explores key dimensions of XD: Close collaboration among interdisciplinary teams, rapid iteration and ongoing user validation. We cover the processes, methodologies, tools, techniques and best-practices practitioners use throughout the entire product development life-cycle, as ideas are transformed to into positive experiences which lead to perpetual customer engagement and brand loyalty. Style and approach An easy-to-understand guide, filled with real-world use cases on process, design, and techniques, helping you build a strong foundation in Experience Design.
Amazing Java: Learn Java Quickly
¥24.44
Amazing Java: Learn Java Quickly
Sorting Algorithms In Computer Programming: Volume 1
¥163.50
Sorting Algorithms In Computer Programming: Volume 1
Secrets of Lookup: Become More Poductive With Vlookup Free Your Time
¥24.44
Secrets of Lookup: Become More Poductive With Vlookup Free Your Time
Secrets of MS Excel VBA Macros for Beginners !: Save Your Time With Visual Basic
¥24.44
Secrets of MS Excel VBA Macros for Beginners !: Save Your Time With Visual Basic Macros!
How To Jailbreak Amazon Fire Stick TV Alexa: How to Unlock Channels & Apps Step
¥40.79
How To Jailbreak Amazon Fire Stick TV Alexa: How to Unlock Channels & Apps Step by Step Guide
Python: Best Practices to Programming Code with Python
¥24.44
Python: Best Practices to Programming Code with Python
JavaScript: Advanced Guide to Programming Code with JavaScript
¥24.44
JavaScript: Advanced Guide to Programming Code with JavaScript
JavaScript: Best Practices to Programming Code with JavaScript
¥24.44
JavaScript: Best Practices to Programming Code with JavaScript
Python: Advanced Guide to Programming Code with Python
¥24.44
Python: Advanced Guide to Programming Code with Python
50 most powerful Excel Functions and Formulas
¥24.44
50 most powerful Excel Functions and Formulas